CDK8 Promotes Cell Proliferation, Migration and Invasion in Esophageal Squamous Cell Carcinoma Through JAK/ STAT3/EMT Pathway

CDK8通过JAK2/STAT3/EMT途径促进食管鳞状细胞癌的细胞增殖、迁移和侵袭

Objective To investigate the expression of cyclin-dependent kinase 8(CDK8)in esophageal squamous cell carcinoma(ESCC)and its effect on ESCC cells,and to explore its potential molecular mechanism.Methods The expression level of CDK8 mRNA was analyzed using UALCAN database,and then the expression level of CDK8 protein in tumor tissues of ESCC patients was detected by immunohistochemistry(IHC).Esophageal cancer cell lines Kyse-30 and Kyse-150 were stably transfected with lentivirus to achieve knockdown and overexpression of CDK8.EdU proliferation assay,cell colony formation assay,cell cycle assay,cell scratch assay and invasion assay were used to explore the effect of CDK8 protein expression level on the phenotype of ESCC cells.Subsequently,the effect of CDK8 on the growth of esophageal cancer xenografts in vitro was observed by subcutaneous tumor formation assay in mice.Finally,the expression of proliferation and metastasis related proteins was detected by Western blot.Results CDK8 showed high transcription and protein expression levels in ESCC tissues compared with normal esophageal tissues.Knockdown of CDK8 expression significantly inhibited the proliferation,migration and invasion of ESCC cells.In addition,inhibition of CDK8 expression significantly affected the JAK2/STAT3 pathway and the expression of E-cadherin/N-cadherin,while overexpression of CDK8 reversed these effects.Inhibition of STAT3 pathway reversed the promoting effect of CDK8 overexpression on ESCC cell phenotype.Conclusion CDK8 is a cancer-promoting factor of ESCC,which mediates the phosphorylation of JAK2/STAT3 and epithelial-mesenchymal transition(EMT).

目的本研究旨在探究细胞周期蛋白依赖性激酶8(cyclin-dependent kinase 8,CDK8)在食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)中的表达及其对ESCC细胞的影响,并探讨潜在的分子机制。方法首先通过UALCAN数据库分析了CDK8 m RNA的表达水平,然后利用免疫组织化学技术检测了CDK8蛋白在ESCC患者肿瘤组织中的表达水平。利用慢病毒稳定转染食管癌Kyse-30及Kyse-150细胞株以敲低或过表达CDK8,通过Ed U增殖实验、细胞集落形成实验、细胞周期实验、细胞划痕实验和侵袭实验等多种方法探究CDK8蛋白表达水平的改变对食管癌细胞表型的影响。随后,通过小鼠皮下成瘤试验观察CDK8对体外食管癌移植瘤生长的影响。最后通过蛋白质印迹法检测增殖和转移相关蛋白质的表达情况。结果与正常食管组织相比,CDK8在ESCC组织中转录和蛋白质表达水平均较高。敲低CDK8的表达能够显著抑制ESCC细胞的增殖、迁移和侵袭;此外,抑制CDK8表达可显著影响JAK2/STAT3通路以及E-cadherin/N-cadherin/Vimentin的表达,过表达CDK8则可以逆转上述结果,抑制STAT3通路逆转了CDK8过表达对ESCC细胞表型的促进作用。结论CDK8是ESCC的促癌因子,可介导JAK2/STAT3磷酸化水平以及上皮-间充质转化(epithelialmesenchymal transition,EMT)的过程。